High Quality Content by WIKIPEDIA articles! Saccharomyces florentinus is a plant pathogen. A pathogen, (from Greek pathos "suffering, passion", and ( -) gignomai (gen-) "I give birth to") an infectious agent, or more commonly germ, is a biological agent that causes disease to its host. There are several substrates and pathways whereby pathogens can invade a host; the principal pathways have different episodic time frames, but soil contamination has the longest or most persistent potential for harboring a pathogen.